Modular architectural cistern



FIG. 1 is a perspective view of a modular architectural cistern showing my new design;

FIG. 2 is a top side view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a front view thereof

FIG. 5 is a right side view thereof;

FIG. 6 is a back view thereof; and,

FIG. 7 is another perspective view thereof.

The broken lines illustrate portions of the modular architectural cistern that do not form a part of the claimed design. 

CLAIM The ornamental design for a modular architectural cistern, as shown. 